hz glass ceramics enable flexible dental restoration …...2016/05/11  · glass ceramics enable...

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FRAUNHOFER INSTITUTE FOR SILICATE RESEARCH ISC GLASS CERAMICS ENABLE FLEXIBLE DENTAL RESTORATION Glass ceramics as restorative material In many cases glass ceramics are very suita- ble for dental restoration. The translucency (partial transparency) and the mechanical properties (e. g. strenght and polishing be- haviour) can be adjusted via the crystalline components like crystal size and phase frac- tions. In comparison to pure glass the che- mical resistance is even better – an impor- tant aspect for its use in oral environment. Chair site production For CAD/CAM applications another material‘s property is essential: In an intermediate state during the crystallization process the material can be mechanically machined easily. Afterwards the material can be transformed in just one annealing step to the final high-tensile glass ceramic. 1 From the block to the final ve- neer Fraunhofer Institute for Silicate Research ISC Neunerplatz 2 97082 Würzburg, Germany Competence Unit Glass and Mineral Materials Dr. Martin Kilo Phone +49 931 4100-234 [email protected] Dr. Bernhard Durschang Pone +49 931 4100-304 [email protected] www.isc.fraunhofer.de 2 1 3 State of the art Virtually all companies active in the field of dental supplies provide CAD/CAM systems for all-ceramic restorations. The big advan- tage of this method is that in a single ses- sion – the so called chair-side technique – a high-quality and individually customized dental product can be manufactured during the treatment of the patient. Compared to the classic two- or multi-step procedu- re with temporaries this leads to an emi- nent efficiency gain saving a great amount of time and costs for both the patient and the dentist. The chair-side technique consists of the fol- lowing steps: Recording of the tooth or the teeth to be restored with an intraoral camera Computation and processing of a restoration model with computer (CAD) 1

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Page 1: HZ Glass ceramics enable flexible dental restoration …...2016/05/11  · glass ceramics enable flexible dental restoration Glass ceramics as restorative material In many cases glass

F R A U N H O F E R I N S T I T U T E F O R S I l I c AT E R E S E A R c H I S c

glass ceramics enableflexible dental restoration

Glass ceramics as restorative material

In many cases glass ceramics are very suita-

ble for dental restoration. The translucency

(partial transparency) and the mechanical

properties (e. g. strenght and polishing be-

haviour) can be adjusted via the crystalline

components like crystal size and phase frac-

tions. In comparison to pure glass the che-

mical resistance is even better – an impor-

tant aspect for its use in oral environment.

chair site production

For CAD/CAM applications another

material‘s property is essential: In an

intermediate state during the crystallization

process the material can be mechanically

machined easily. Afterwards the material

can be transformed in just one annealing

step to the final high-tensile glass ceramic.

1 From the block to the final ve-

neer

Fraunhofer Institute for

Silicate Research ISc

Neunerplatz 2

97082 Würzburg, Germany

Competence Unit Glass and

Mineral Materials

Dr. Martin Kilo

Phone +49 931 4100-234

[email protected]

Dr. Bernhard Durschang

Pone +49 931 4100-304

[email protected]

www.isc.fraunhofer.de

21 3

State of the art

Virtually all companies active in the field of

dental supplies provide CAD/CAM systems

for all-ceramic restorations. The big advan-

tage of this method is that in a single ses-

sion – the so called chair-side technique –

a high-quality and individually customized

dental product can be manufactured during

the treatment of the patient. Compared

to the classic two- or multi-step procedu-

re with temporaries this leads to an emi-

nent efficiency gain saving a great amount

of time and costs for both the patient and

the dentist.

The chair-side technique consists of the fol-

lowing steps:

� Recording of the tooth or the teeth to

be restored with an intraoral camera

� Computation and processing of a

restoration model with computer

(CAD)

1

Page 2: HZ Glass ceramics enable flexible dental restoration …...2016/05/11  · glass ceramics enable flexible dental restoration Glass ceramics as restorative material In many cases glass

� Selection of a blank with respect to

size and colour of the existing teeth

� Milling out the restoration of the blank

with a milling/grinding unit,

e. g. CEREC (CAD)

� Thermal after-treatment in less than 30

minutes to increase the strength

� Gluing/cementing of the restoration

(crowns, inlays, onlays, veneers, etc.)

Prior to gluing the dental crown/bridge ad-

ditional veneering materials can be added

which can be tempered to achieve a certain

colour gradient according to the patient‘s

wishes.

The new material

In collaboration with DeguDent GmbH (Ha-

nau) and VITA Zahnfabrik H. Rauter GmbH

& Co. KG (Bad Säckingen) the Fraunhofer

ISC has developed a novel glass ceramic

base system and an adapted production

method.

The patented new glass ceramic base sys-

tem has an excellent translucency, high

chemical resistance and great strength.

With the current available dental CAM sys-

tems the material can be processed within

a wide range of crystallization parameters.

The base material converts very quickly into

the final state and retains its shape.

Furthermore, the colouring can be easily

adjusted and finally processed by the den-

tist (e. g. polishing).

The competence unit Glass and Mineral

Materials at Fraunhofer ISC developed the

new material as well as the production pro-

cess in accordance with medical guidelines

and required QM measures.

Both industry partners introduced the new

material into the market under the trade

names Suprinity® and Celtra®.

Material properties

The new glass ceramics have higher glass

matrix portions than glass ceramics contai-

ning no or only small amounts of ZrO2 and

thereby show excellent optical properties.

Despite the relatively high proportion of

glass phase, the newly developed glass ce-

ramics show at least equal chemical resis-

tance whereas the mechanical properties

are significantly superior to previous availa-

ble products. As a characteristic of mecha-

nical stability in dental applications the

standardized 3-point flexural strength is gi-

ven. The lithium silicate glass ceramics rein-

forced with zirconium oxide (ZLS) exhibit

considerably higher flexural strengths (up

to 450-500 MPa) than common products.

Due to the high values aesthetically superi-

or glass ceramics can be applied for molar

bridges (i. e. in the molar region, with the

highest requirements for strength) for the

first time.

What’s more, the common 2-step crystalli-

zation process is no longer necesseary.

Previous CAD/CAM materials are only avail-

able with a flexural strength up to 200 MPa

and require a more than 30 minutes lasting

thermal treatment at about 800 °C and hig-

her to get enough flexural strengh (sintering

or crystallization of (glass) ceramics).

Due to the very fine texture and the high

glass matrix portion the final crystallized

product can be processed with common

CAM units despites its flexural strength up

to 500 MPa (!). The new glass ceramic can

be applied with conventional 2-step me-

thod as well as with the single step pro-

cess. This is a tremendous advantage for an

efficient dental treatment.

die neue dna hochfester GLaskeramik

Der Film

www.degudent-celtra.dewww.dentsply-celtra.de